It’s not as famous as the Monterey Bay Aquarium or as old as San Francisco’s Steinhart Aquarium, but after two decades atop a bluff in La Jolla the Birch Aquarium has established itself as an integral part of the San Diego experience.

The Birch Aquarium celebrated its 20th anniversary in September, unveiling a new logo as leaders explore new technologies to connect the public with research at the Scripps Institution of Oceanography, part of UC San Diego. The third decade probably won’t bring major changes to the aquarium’s footprint, but officials are hoping to expand their educational reach farther into the deep sea and into San Diego County.

California aquariums

The Association of Zoos & Aquariums has accredited seven aquariums in California, listed by the year that they opened:

Aquarium of the Bay, San Francisco (2000)

Aquarium of the Pacific, Long Beach (1998)

Birch Aquarium, La Jolla (1992)

Cabrillo Marine Aquarium, San Pedro (1935)

Monterey Bay Aquarium (1984)

SeaWorld San Diego (1964)

Steinhart Aquarium, San Francisco (1923)

“We’d like to provide more services for our community — become more of a destination,” said Scripps director Tony Haymet. “We’d like to develop our exhibits so that people want to spend just a little more time there.”

From the start, the Birch Aquarium positioned itself as what Haymet calls the “window into Scripps” — the place where the community could glimpse world-class science. It’s still one of the few aquariums in the nation that’s part of a major oceanographic research institution, and it offers earth science education to more than 40,000 schoolchildren a year.

The formula seems to be working. The aquarium recently reported an annual attendance record, with 436,000 people streaming past the iconic sculpture of gray whales breaching near the front gate. The aquarium also has taken a leadership role in climate change education with a major exhibit called “Feeling that Heat” that won international acclaim for the way it addressed the politically touchy subject.

In 1915 — well before global warming became a topic of concern — Scripps erected its first building dedicated solely as an aquarium on campus. It contained 19 tanks ranging from 96 gallons to 228 gallons.

“Even at the beginning of the institution … the scientists were making new discoveries about the life that was living right out here (off La Jolla), and they would be bringing live organisms in. The public would be really interested to know what they had found,” said Debbie Zmarzly, a project scientist and exhibit curator at Birch Aquarium.

In 1951, a new Scripps Aquarium-Museum opened and served for roughly 40 years before giving way to the Birch, which was envisioned as a way to cement San Diego’s position as a marine science hub.

“If we can lure (children) into the sciences and issues of environmental concern, many of the things we do here will be enormously worthwhile,” former Scripps Director Edward Frieman told several hundred officials, donors and friends when the Birch Aquarium broke ground in 1989.

The concept of a new building for the Scripps “window” became a reality thanks in part to a $6 million gift from the Delaware-based Stephen and Mary Birch Foundation, which has given prolific amounts of money to numerous nonprofits in the region.

The $14 million building more than doubled the size of the Scripps aquarium. It features about 60 tanks, including the signature 70,000-gallon kelp forest enclosure and a 13,000-gallon shark tank.

“Everything was able to expand,” Zmarzly said.

Despite excitement about the new digs, the Birch Aquarium wasn’t universally embraced when it opened. An architecture critic for The San Diego Union-Tribune in 1992 said the “two-toned stucco complex already looks dated and deflated,” joining the ranks of those local buildings “to resent for coastal degradation.”

Whatever its aesthetic faults, the aquarium offered locals and tourists much more than previous buildings. In 2002, Nigella Hillgarth, an Oxford-educated zoologist, took the helm and set about planning for a major climate change exhibit before the topic emerged in Al Gore’s movie “An Inconvenient Truth” and catalyzed a national debate.

“(It) seemed important to provide the public with well-informed science from world experts at Scripps,” Hillgarth said by email last week during travels to the Galapagos Islands. “(It) has been far more successful than (I) imagined possible.”

Zmarzly said the aquarium team “worked very hard to purge any possible vestige of politics or ideology from the exhibit.” That didn’t prevent “Feeling the Heat” from generating some complaints, but it also has become a case study for other aquariums and museums that lacked Birch’s scientific backing. In addition, it broadened horizons at Birch.

“I think about the climate exhibit as sort of a transformative exhibit for us in terms of the size and scope and our ability to represent the research,” Zmarzly said. “Before that, everything had been done on a much smaller and less comprehensive scale.”

The climate exhibit remains up while Zmarzly works on a new vision for exploring the deep ocean — an enterprise that could include high-tech tools such as wall-sized interactive video screens.

For now, visitors can learn about nearshore waters at the giant kelp tank, where viewers flock when trained divers enter the tank during the regular narrated feeding sessions. Other popular attractions include displays of the eerily beautiful jellies and the delicate seahorses.

“We have definitely made a dent in the aquarium field as far as seahorses are concerned,” said Fernando Nosratpour, interim aquarium curator. “We have bred and raised about 13 different species, (and) we have shipped out probably close to 3,000 specimens to other aquariums around the world.”

While aquariums regularly swap species, Nosratpour said Birch keeps a boat at the Scripps Pier and scuba divers gather local animals under permits that allow for scientific collecting. “Most of what we need is right here,” he said. “We want to show people a little view, a little slice, of what is out there.”

Likewise, the aquarium pumps seawater from the Scripps pier and filters it for use by a few thousand creatures that live at Birch. Nosratpour said most of the feed is purchased from a restaurant-quality supplier, or shipped by companies that specialize in the tiny shrimplike krill.

Nosratpour said connections between the aquarium staff and Scripps researchers have grown during the Birch era, sometimes in ways that aren’t obvious to the public. For instance, the aquarium has raised so many coral and jellies that it lets scientists use them for experiments instead of taking samples from the wild.

”We feel that we are helping … to conserve the animals,” Nosratpour said. “We are happy to be engaged in at least a little way to help research.”